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Topic Review (Newest First)

11-12-2013 01:32 PM

mustang 671

Quote:

Originally Posted by ProStreetRob

Believe me 671 I can relate on not having a local track They closed each and every track within a 100+ miles of my house and sometimes for me it's a 2 day routine to simply go make a few passes, it's a real pita...
BUT IT'S WORTH IT WHEN YOUR THERE AND DOING IT

I am getting on with my engine. seem to be going around in circles on here. I cant change my bottom pulley. so I have to change my top each time I want a boost change. am thinking of ordered up a 47 and 43 top pulley but waiting for the blower shop to get back to me on expected boost based on what I have told them with my engine figures and current blower sizes.

prob go back to dyno over xmas. I like the dyno for testing out. more safer and controlled rather than hoping and screaming down a track. I will do that when its set up.

11-06-2013 08:08 PM

ProStreetRob

Believe me 671 I can relate on not having a local track They closed each and every track within a 100+ miles of my house and sometimes for me it's a 2 day routine to simply go make a few passes, it's a real pita...
BUT IT'S WORTH IT WHEN YOUR THERE AND DOING IT

Here's my passes from Sat, make no mistake these 351w can kick some *** when they're making power

No point . As the 1/4 mile track is 3. Hrs from me . Dyno wouldn't be that far out -ie 150 bhp more is still only. 480 bhp . Which is where I wanted to start from . 550--600 bhp is more than do able with what ive built . Eveerything is new . All readings at dyno where good . Have plenty more to go . Need more boost . Some. Standard 350s are making this power,

Need help on pulleys if you can ,

Point taken though and I will go to the track . Once im seeing more power

11-06-2013 01:35 AM

mustang 671

Yes they are opening fully . Pri jets 72 second jets 78 did change secoundaries to 82 but no power increase just highest air fuel mix .ign mapped by dyno guys for peak bhp . Gave it what it wanted . Needs more boost . Any ideas on pulleys ? Fuel prressure maintained .

11-05-2013 12:50 PM

mustang 671

Quote:

Originally Posted by F-BIRD'88

Vacuum secondary throttles opening?

yes they re fine

11-05-2013 12:46 PM

mustang 671

Quote:

Originally Posted by F-BIRD'88

The "eddy current" type dynos give the most conservative power numbers.
Transmission: There is more to it than just fluid level.
High stall converter efficiency.
High /direct clutches.
Tire slip. Tire distortion on rollers.
Exhaust

hi fire bird.

have just posted below my auto c6 spec. its all new and good quality stuff.

tyres are brand new. they sprayed some goo onto the rollers for it to grip.

the exhaust I also mentioned. but agree if it had a stainless all the way through im sure it would flow better. but it is big bore . and I have nice long headers. large bore aswell.

11-05-2013 12:38 PM

mustang 671

hi all and those just following . I really could do with some input on the following. and I know it may be a wet finger in the air and hope ????

so currently I have a 45 tooth bottom and 51 tooth top pulley. I got 7psi at 6000rpm but had so much more to go and only produced 330bhp.

have spoken with the dyno guys again today and also a supplier over your neck of the woods who can supply me with a 42 tooth cog for $115 + delivery which isn't bad. my questions is , can anyone hazard a good guess- work out? how much boost that would get me to ? so 45 bottom and 42 top

my engine started at 7.48to1 comp ratio but since then I have changed from a felpro normal head gasket to a felpro mls one. nothing else has been changed apart from it being homed out just slightly and a bit of piston to bore wear but prob nothing to be honest as the engine hasn't had much use. the orginal block is 30 thou over and I have kb hyper pistons - but I do now have a new crane custom grind cam which I posted about earlier which is a roller cam.

I have large headers which collect and go into 3" exhausts . under and out the back. the car was for racing before I imported it so it has a large dual exhaust.

I have a c6 with a high stall b+m torque converter. Been uprated with reverse manual shift pattern body.

my thoughts are that the combi would give around 10-12 psi ? which would be a lot better , I will have the water inj running with this higher boost. I can easily get hold of 99 octane fuel to use. only 5p a litre more . but still bloody £6.58 a gallon

help !!!!!!!

11-05-2013 12:16 PM

mustang 671

Quote:

Originally Posted by bentwings

Somewhere above you were talking about the boost not being what the charts showed. It's possible you have a small case 6-71. Not a problem but you just have to spin it faster. Hopefully your blower is not messed up. I've run into at least 6 this year with too little clearance on the rear of the rotors resulting in a galled case and rotors.

Since you can't change the bottom pulley the only choice is the top one. You may have to make a spacer under the blower. 1/8, 3/16 and 1/4 in are common SAE sizes. Adjust for metric material if you need to. The reason for the spacers is that you you may run out of room for adjustment on the idler.

hi bent wings.

thanks for the comment. I can get a different size belt so haven't got any issues with the tensioning luckily. that's interesting you mention it could be a smaller case blower. will look into that. ta

also I looked at my blower before I brought it years ago and also more recently when I o-ringed out the inlet manifold. the rotors are good. no scores. no leaks from the blower either.

11-05-2013 12:14 PM

mustang 671

hi pro street rob

the sierra sounds nice on the rd. and congrats on those times. must be hard when its raining. here in the uk the weather has turned so don't expect I will be getting out much for a few months, prob not a bad thing. try and get some nice cold dry days and put some miles o it before the summer heat comes. less chance of it getting too hot. your pulley sizes are interesting. seems the charts aren't any use and just a very very rough guide.

11-03-2013 10:53 AM

bentwings

Somewhere above you were talking about the boost not being what the charts showed. It's possible you have a small case 6-71. Not a problem but you just have to spin it faster. Hopefully your blower is not messed up. I've run into at least 6 this year with too little clearance on the rear of the rotors resulting in a galled case and rotors.

Since you can't change the bottom pulley the only choice is the top one. You may have to make a spacer under the blower. 1/8, 3/16 and 1/4 in are common SAE sizes. Adjust for metric material if you need to. The reason for the spacers is that you you may run out of room for adjustment on the idler.

11-02-2013 09:29 PM

ProStreetRob

Quote:

Originally Posted by mustang 671

how did you get on ??

I agree its 11% underdriven . what's your thoughts on going 1 to 1 ?

haven't a clue on dyno or sae numbers etc. suppose I thought its their job to do all of that ? give me some pointers to ask them ?? the dyno works the opposite to a alternator and uses electric current to operate . does that help ?

they did say that you "yanks " lol . do inflate dyno numbers ?? ie the bhp over there is different to here ? I know that seems mad and I don't think they mean its a different value . for example, they had some dick head who had a corvette and he raved that it was a 500 bhp car. the most the dyno saw was 375 . now that could of been 500 bhp at the fly wheel ?

think they have just had a few big v8s go in there saying this and that and when it comes down to it the power isn't there.

they like the idea of my water inj. said to get it as good as it can then slightly back off and use water inj to add some intercool charge.

have heard that methanol rots alu ? failing me getting a refrigeration coil put into the tank what other liquid can I use with water to provide intercooled effect ? I read somewhere on here windscreen wiper cleaning liquid -screen wash ???? really ??

what boost you run with blown engine ? what comp ratio ?

The track was bad today, we had 2 rain delays, 2 MASSIVE OIL DOWNS, and I spent probably an easy 4 hours sitting in the staging lanes
Deep Staged by mistake on the first pass and ran a 10.92, then ran a 10.81 and the best ET of the day was 10.70 (it went 10.66 & 10.61 at Atco earlier this year) Atco is a much better track and closer to sea level where Island is up in the mountains at higher elevation so I guess I cant complain since we took it home in one piece

As for the Street Beast, my Sierra makes crazy power so I dont need much boost. I'm running a 56 T Upper Pulley + 52T Lower Pulley =’s 8 lbs of Boost @ 6,000 RPM (-5.5 Underdriven). At that set up the compression correction works out to 13.1 Compression. If I switch the pulleys around it's 12 lbs of Boost @ 6,000 RPM (+5.8 Overdriven) With that set up the compression correction works out to be 15.1

And I also agree the power seems low, do you know if it was a Dynojet or Mustang Dyno ??? and were the numbers SAE, Net, or Uncorrected ???
Those #'s could be off by as much as 15% and as also said the 1320 dont lie, MPH will tell EVERYTHING.

AMOF I'm leaving right this sec to go out of State and take my 351W down the 1320 for the last time this season, (hoping for a 10.5 this time out)

how did you get on ??

I agree its 11% underdriven . what's your thoughts on going 1 to 1 ?

haven't a clue on dyno or sae numbers etc. suppose I thought its their job to do all of that ? give me some pointers to ask them ?? the dyno works the opposite to a alternator and uses electric current to operate . does that help ?

they did say that you "yanks " lol . do inflate dyno numbers ?? ie the bhp over there is different to here ? I know that seems mad and I don't think they mean its a different value . for example, they had some dick head who had a corvette and he raved that it was a 500 bhp car. the most the dyno saw was 375 . now that could of been 500 bhp at the fly wheel ?

think they have just had a few big v8s go in there saying this and that and when it comes down to it the power isn't there.

they like the idea of my water inj. said to get it as good as it can then slightly back off and use water inj to add some intercool charge.

have heard that methanol rots alu ? failing me getting a refrigeration coil put into the tank what other liquid can I use with water to provide intercooled effect ? I read somewhere on here windscreen wiper cleaning liquid -screen wash ???? really ??

what boost you run with blown engine ? what comp ratio ?

11-02-2013 10:17 AM

mustang 671

Quote:

Originally Posted by F-BIRD'88

Vacuum secondary throttles opening?

yes , I watched them open , was sticky before so we changed both diaphrams. check ball has been removed, I boost ref the primary metering blocks so the pv's see manifold vacuum as we discussed a while ago. didn't do the work on the carb base. did it using the take off tubes already on the primary metering blocks and opened the channel to the pv's

11-02-2013 10:06 AM

mustang 671

Quote:

Originally Posted by F-BIRD'88

When calibrated correctly chassis dynos give very modest power numbers.
There are many factors.
You should have removed the engine and dynoed it on a real engine dyno.

the blower drive ratio is 11%under. If you are sure of the carb jetting
you can change it to 11% over by reversing the top and bottom pulleys.
Reduce the timing and sneek back up on it once verifying the tune
and knock tolerance.
The exhaust many be killing it.
Verify dyno calibration and setup. And weather correction factor etc.

Even at 7psi and 11% under drive I would expect more horsepower from it.
The ignition system is very suspect.
Tire traction.. A transmission issue.

hi firebird

wish I could change the pulleys around but I cant move the bottom one. its been made to fit over the harmonic balancer , so am thinking of ordering the same size as the bottom one and running it 1 to 1 . seems the holley/weiand charts are very out for my engine, I understand they do say its only a guide. but its way out. meant to be 11psi on their charts but not even seeing 7psi at 6000 rpm,

on the ignition I cant see any problems, new plugs , double checked with a timing light. I was at the dyno for 6 hrs with them, carbs off 4 times, re jetting, changed the vac sec diaphragm's. once it made max power it didn't move even when it was jetted richer , secondary's worked fine, pvs coming in nicely

they sprayed some compound on the tires to make it grip, I do have a auto so am sure im loosing bhp through trans, but I checked it before they started and it was full of atf.

I have racked as most brains as I can and all point towards more boost.

points noted and will double and triple check plugs ,auto fluid. I have took my carbs off AGAIN and am stripping them down tomorrow just to double check there is not debris or obstructions.

And I also agree the power seems low, do you know if it was a Dynojet or Mustang Dyno ??? and were the numbers SAE, Net, or Uncorrected ???
Those #'s could be off by as much as 15% and as also said the 1320 dont lie, MPH will tell EVERYTHING.

AMOF I'm leaving right this sec to go out of State and take my 351W down the 1320 for the last time this season, (hoping for a 10.5 this time out)

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